In immunology, activation is the transition of leucocytes and other cell types involved in the immune system. On the other hand, deactivation is the transition in the reverse direction.[1] This balance is tightly regulated, since a too small degree of activation causes susceptibility to infections, while, on the other hand, a too large degree of activation causes autoimmune diseases.
Activation and deactivation results from a variety of factors, including cytokines, soluble receptors, arachidonic acid metabolites, steroids, receptor antagonists, adhesion molecules, bacterial products and viral products.
| Cytokines | ||
|---|---|---|
| Soluble receptors | ||
| Arachidonic acid metabolites | ||
| Steroids | ||
| Receptor antagonists | ||
| Adhesion molecules |
| |
| Bacterial products |
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| Viral products |
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